Welcome Tomer, I'm glad you've found us! Apologies for the slow reply – we're on holidays at the moment.
1 – Absolutely. Use whatever tools your feel comfortable with, in order to showcase your skills in the best possible light. There is no recognised standard.
2 – Not that I have ever heard of, but that doesn't mean it's not the case.
3 – That really depends on the area in which you want to work. The idea is to showcase your process as much as the finished product/
4 – No, as above – the premise of UX is the process, although design skills are a definite plus.
5 – The more detail the better.